An ideal inverting op-amp circuit is to be designed with a closed-loop voltage gain of \(A_{v}=-1000\). The largest resistor value to be used is \(500 \mathrm{k} \Omega\).

(a) If the simple two-resistor design shown in Figure 9.8 is used, what is the input resistance?

(b) If the T-network design shown in Figure 9.12 with \(R_{3}=500 \mathrm{k} \Omega\) and \(R_{2}=R_{4}=250 \mathrm{k} \Omega\) is used, what is the input resistance?

Figure 9.8:-

R ww 2) + R ww Figure 9.8 Inverting op-amp circuit